Practice, not loss of sight, improves sense of touch in the blind: study

May 11, 2011
A photo of the device used in the fingertips experiments

New research from McMaster University may answer a controversial question: do the blind have a better sense of touch because the brain compensates for vision loss or because of heavy reliance on their fingertips?

The study, published in the most recent edition of the , suggests daily dependence on touch is the answer.

Twenty-eight profoundly blind participants—with varying degrees of Braille expertise—and 55 normally sighted adults were tested for touch sensitivity on six fingers and both sides of the lower lip.

Researchers reasoned that, if daily dependence on touch improves tactile sensitivity, then blind participants would outperform the sighted on all fingers, and blind Braille readers would show particular sensitivity on their reading fingers. But if alone improves tactile sensitivity, then blind participants would outperform the sighted on all body areas, even those that blind and sighted people use equally often, such as the lips.

"There have always been these two competing ideas about why blind people have a better sense of touch," explains Daniel Goldreich, corresponding author and a professor in the Department of Psychology, Neuroscience & Behaviour. "We found that dependence on touch is a driving force here. Proficient Braille readers—those who might spend hours a day reading with their —performed remarkably better. But blind and sighted participants performed equally when the lips were tested for sensitivity."

Researchers used a specially-designed machine which held the pad of the participant's fingertip perfectly still for the experiments. While the finger lay over a hole in the table, the machine pushed rods with textured surfaces through the opening until they met the fingertip. Researchers asked subjects to identify the patterns by touch. A similar test was performed on the lower lip.

Not only did blind participants do better than their sighted peers, but Braille readers, when tested on their readings hands, outperformed nonreaders who were also blind. For Braille-reading participants, their reading fingers were more sensitive than their non-reading fingers.

"These results may help us design further experiments to determine how to improve the , which could have applications later in life," says Mike Wong, study author and a graduate student in the McMaster Integrative Neuroscience Discovery & Study program. "Braille is extraordinarily difficult to master, particularly as an adult. In future we may find new ways to teach to people who have recently become blind."

More information: A pdf of the study can be found at: dailynews.mcmaster.ca/images/Blindnesstouch.pdf

Related Stories

Recommended for you

The neural codes for body movements

July 21, 2017
A small patch of neurons in the brain can encode the movements of many body parts, according to researchers in the laboratory of Caltech's Richard Andersen, James G. Boswell Professor of Neuroscience, Tianqiao and Chrissy ...

Faulty support cells disrupt communication in brains of people with schizophrenia

July 20, 2017
New research has identified the culprit behind the wiring problems in the brains of people with schizophrenia. When researchers transplanted human brain cells generated from individuals diagnosed with childhood-onset schizophrenia ...

Scientists reveal how patterns of brain activity direct specific body movements

July 20, 2017
New research by Columbia scientists offers fresh insight into how the brain tells the body to move, from simple behaviors like walking, to trained movements that may take years to master. The discovery in mice advances knowledge ...

Scientists discover combined sensory map for heat, humidity in fly brain

July 20, 2017
Northwestern University neuroscientists now can visualize how fruit flies sense and process humidity and temperature together through a "sensory map" within their brains, according to new research.

Team traces masculinization in mice to estrogen receptor in inhibitory neurons

July 20, 2017
Researchers at Cold Spring Harbor Laboratory (CSHL) have opened a black box in the brain whose contents explain one of the remarkable yet mysterious facts of life.

Speech language therapy delivered through the Internet leads to similar improvements as in-person treatment

July 20, 2017
Telerehabilitation helps healthcare professionals reach more patients in need, but some worry it doesn't offer the same quality of care as in-person treatment. This isn't the case, according to recent research by Baycrest.

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

klawy
4 / 5 (1) May 11, 2011
Anybody that is suprised? The brain can never just compensate - you have to learn and learn through practice. Can't realy belive that someone puts money and effort in to this - it might sound logic at a first glance. Turn it the other way around does your vision improve because you loose your sense of feeling... Why not blindfold people for 8h a day and see if there sense of touch is improved... Seriously... Do we need to test that hypothesis too?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.